The present disclosure is directed spacecraft and, more particularly, to spacecraft propellant tank mount systems.
It is desirable to minimize the mass or weight (i.e., the force exerted on a mass by Earth's gravity) of a spacecraft. Each kilogram of spacecraft mass that is to be launched into Earth orbit may require as much as 10 kilograms of fuel. Accordingly, it is desirable to minimize spacecraft mass in order to reduce the overall cost and fuel requirements of a launch vehicle. Further, by reducing the mass of the spacecraft propulsion structure, more available spacecraft mass may be devoted to instrumentation and other spacecraft payload. One mechanism for reducing spacecraft mass is to eliminate any unnecessary structure from the spacecraft.
These considerations apply to spacecraft powered by electric propulsion systems, as well as to spacecraft that may employ chemical, or hybrid propulsion systems. Currently, spacecraft of the type having a central thrust tube design require internal propellant tanks that match the tube diameter to transfer launch loads to the cylindrical wall of the central thrust tube with minimal bending. A disadvantage with such a design is that it may require a custom tank design to match the inside diameter of the central thrust tube. Further, such a design may not work well with electric propulsion spacecraft because the size of the propellant tank required by a mission may be less than what would be required to fill the interior of the central thrust tube. Accordingly, there is a need for a spacecraft having a propellant tank mount that may be used in conjunction with a central thrust tube, but does not need to match the interior diameter of the central thrust tube.